This expansive already used `wide-ranging'.aa essay recounts how the novelist John Updike (the ``U'' of the title) has wielded an uncanny influence on fellow novelist Baker ( The Mezzanine ). Baker calls the genre here ``memory criticism,'' a form that ``relies entirely on what has survived in a reader's mind from a particular writer over at least ten gs years of spotty perusal.'' Alternately self-deprecating (``What's he Baker done that is so good that he thinks he can freely criticize Updike?'') and self-aggrandizing ( ``Do you think I'm a better writer than Updike?'' since you say he's talking to his wife, I'm not sure if double quotes are needed. aa Baker asks his future wife), the book presents a telling portrait of a working writer and critic. This is not a primitive, adulatory dialogue with the oeuvreok? of a lofty father figure; rather, it is a quivering ``imaginary friendship'' with living literary kin. Like all good essays, these are full of fertile tangential thoughts, as in Baker's delineation of one of the ``risks'' that he believes is implicit in memory criticism: ``It depends to an unusual extent on whether you the reader like me.'' Such thoughts stay in the mind long after annoyingly arch self-commentary--``my entire buttock region, as day-glo-sic colored as a baboon's''--has been and gone. First serial to the Atlantic; author tour. (Apr.)